I liked the beginning with the explanation of Demyx's double life and how it's described. If it's going to continue like other fanfictions featuring this idea, that's not necessarily bad, but try to make it original and believable. This site doesn't really need another story with the new kids instantly being attracted to their specific "match". (Riku/Sora; Axel/Roxas)

Also, the dialogue itself (the words) has no real issue and serves its purpose, but the way its presented is a little off. I don't mean to act like a grammar-nazi, but the story would simply look better if the conversations where properly set up.

Anyway, looking forward to how you add to this (and to the possibility that there could be Demyx/Zexion .), nice start. : )